Wave intensity analysis

Researchers at ICCH have developed completely new methods of analysing the
complex interactions between pressure and flow that occur within the coronary arteries
during cardiac contraction and relaxation. Wave Intensity Analysis, pioneered at Imperial
College by collaborative research between Professor Kim Parker and Keith Willson is
one of these methods. This technique measures blood pressure and the speed of
blood flow at the same time and in the same place using special sensor wires placed in the
main blood vessel leading from the heart. This improves understanding of the generation of
blood pressure and factors which influence it.

In his PhD research, Dr John Baksi is using Wave Intensity Analysis to improve our
understanding of how age affects the generation of blood pressure.

As we age, not only does blood pressure rise, but it also becomes more ‘pointy’, with a
bigger and sharper upstroke in pressure. This may contribute to the increased rate of heart
disease and stroke in older people. Doctors used to believe that the reason for the
increase in ‘pointiness’ of blood pressure was that pressure waves, travelling outward from
the heart through the arteries, were more powerfully and quickly ‘reflected’ back towards
the heart. As a result, treatments have been targeting this reflection process.

However, Dr Baksi has recognised that this picture might be false. In a series of
experiments, he is testing the possibility that this change is nothing to do with reflections
at all, but instead, is the result of changes in the pliability of the large arteries.

‘The reason why these drugs are not as effective in preventing heart attack and
stroke as we would like, might be that they are targeting the wrong problem. If
proven, this will make a huge impact on the way we think about, and treat, high
blood pressure, the greatest contributor to preventable cardiovascular death in
the world.’